Improved machine for cutting screws



.To all whom fit may cou-cern 'initrd 5 ca /@Alweatwt JOHN DOUGHERTY, or sA-N FRANCIsCo, CALIFORNiA..

Letters Patent No. 88,460, :lated March 30,1869.

The Schedule referred to in these Letters Patent and making part ofthe siamo.

Beit known that I, JOHN DOUGHERTY, ofthe city and county of San Francisco, and State of California, have invented a new and improved Screw-Gutter; and I- do hereby declare that the following is a full and exact description of the said invention, reference being vhad to the accompanying drawings, in which- `Figure 1 is a perspective view, and v Figure 2, a face view of the worm-wheel'with the cap removed. v

The body ofthe machine consists of the two solid liees, A Aand B B, united rigidly by the vguide-bars Mounted, andsliding upon the guide-bars, is the chair D, having a head, E, and projections, F F, as

shown in g. l.

The worm-wheel G is revolved upon a boss on the head E, by the wormH, having its bearings in the projections F F, and driven by the hand-wheel I. l Through the head E, and its boss, and the worin# wheel, is a round hole, large enough to receive the' largest-sized rod, or pipe, on which a screw is to be cut. r Within the worin-wheel, at the end of the boss, is the universal-chuck, shown in iig. 2.

. fJ J J are ratchet, or eccentric surfaces in the rim .of the wheel, against which run the exterior' ends of the clamp-slides K K K, which slides are held in placepartly bythe sector-:blocks L L L, screwed to the end of the boss, on the head E, and partly by the cap M,

`by the feed-screw P and hand-wheel O, the end of the screw-rod turning freely in the chair, and playing longitudinall y therein for a distance equal to the length of the screw to be cut.

Through the head R, ofthe body-piece A A, and

the bossS,'is a shaft, carrying on lits inner end the die-socket T. g

The die is held in the socket by the circular cap U, swung on a pin, and fastened by a thumb-screw, as shown in iig. 1.

On the outer end of the shaft are the two spurwheels V and lV, one large and the other small, play-V ing into which are corresponding wheels, (only one of which, X, is showin) ou a counter shaft, supported by an arm from the body of the machine.

The wheel nearest to the end of .each sha runsv loose on the shaft, but is so arranged as to be made fast, at pleasure, byapin through its hub and the shaft, or

otherwise. `The other two wheels are fast, each to its shaft. v

This gear admits of 'convenient adj ustment with reference to power and speed, the power being arranged to be applied to either shaft by a crank for the hand,

Gare should be taken not to apply the powerin any other way, or the machinery may be-broken.

The operation is as follows: The pipe or rod on which the screw is to be cut, is passed through the head and worm-wheel E and G. Then, by turning the hand-wheel I'in the proper direction, the rod will be clamped iirrnly at the centre of -the worin-wheel, by the inner ends of the clamp-slides K K K, which are driven against it, by the eccentric surfaces' J J J, wedging over their outer vends, `as in other like devices.

A dieof the proper size is now placed in the die socket, and the power applied, and the die revolved,

By turning the hand-wheel O, the carriage D is now moved forward, till the end of the'pipe reaches the die, and the cutting of the thread has fairly commenced,

after whieh'the machine will feed itself, the slide at the end of the screw-rod P allowing the chair to be drawn forward, while the screw remains stationary.

When suiicient thread has beencut, the motion ,is-

reversed, and the rod withdrawn, `in the ordinary manner.

The peculiar' advantages of my arrangement are, the extent and facility of adjustability as to s eed and power, and the. revolving of the die instead of the chuck, by which rods or pipes of any length or form can be easily worked, and lthe worm-wheel chuck used;

Having thus described my invention,

What I claim as new, and desire to secure by Let ters Patent, is

1. Arranging together, in a screw-threading machine, in the manner described, the feed-screw P, carriage D, worm-wheel H, and worm-chuck Gr, each being constructed as shown and described.

2. The arrangement, on the two rotating shafts, of the loose gears X V, fast gears W, and head-stock S, as and for the purpose specified.

V JOHN DOUGHERTY.

Witnesses:

J. F. Gownnn, ALFRED Rrx. 

